1. Field of the Invention
The present invention relates to a resist pattern which forms a fine pattern suitable for manufacturing a semiconductor device, a method for forming a resist pattern to form the resist pattern efficiently in a short time, a resist material suitable for forming a fine pattern by the resist pattern efficiently in a short time, a semiconductor device comprising a fine pattern formed by the resist pattern, and a method for manufacturing a semiconductor device for manufacturing the semiconductor device efficiently in a short time.
2. Description of the Related Art
The research and development of high performance LSI has been actively pursued for a long time, and in the development of these highly efficient LSI, fine patterning technology and resist materials are key features.
In this fine patterning technology, electron beam lithography in which a resist material is irradiated by an electron beam enables formation of a fine pattern with a width of 0.1 μm or less, and has therefore been extensively studied. As far as concerns highly efficient resist materials, the chemically amplified type resist material proposed by H. Ito of IBM Corp. USA are suitable for this electron beam lithography, and since they offer high resolution and high sensitivity, a great deal of research is being carried out on it (J. M. J. Frechet et al., Proc. Microcircuit Eng., 260 (1982), H. Ito et al., “Polymers in Electronics”, ACS Symposium Series 242, T. Davidson, ed., ACS 11 (1984) and U.S. Pat. No. 4,491,628 (1985)). This chemically amplified type resist material contains a photo-acid generator. If a resist film of this chemically amplified type resist material is exposed to light, such as ultraviolet radiation, an electron beam, X-rays or a focused ion beam, an acid is produced from a photo-acid generator, and the exposed part changes due to a catalytic reaction in a bake performed after the exposure, to an alkali soluble (positive type) or insoluble (negative type) substance. This permits developing to be performed.
Recently, such chemically amplified type resist materials are becoming the materials of choice to form a fine pattern with the aforementioned electron ray lithography technique.
However, in the case of electron ray lithography technique, as compared with conventional lithography techniques in which the resist material is irradiated by UV light, the exposure takes much more time and it is not very efficient.
For this reason, to compensate for the low throughput in the electron beam lithography technique, parts of a resist film formed from a chemically amplified type resist material which form a fine pattern are exposed to an electron beam, and the remaining parts which form relatively large patterns are exposed at high speed to ultraviolet radiation as before.
However, in the case of this method, there are the following problems. In general, an onium salt photo-acid generator with high acid generating efficiency (high quantum yield) is added to the chemically amplified type resist material for the purpose of improving throughput. However, this onium salt photo-acid generator reacts to far ultraviolet radiation having a wavelength of less than 300 nm but not to near-ultraviolet light having a wavelength of 300 nm or more. Thus, in exposing a resist film formed by the chemically amplified type resist material, it cannot be used in an aligner having a g line (wavelength 436 nm) and i line (wavelength 365 nm) exposure device which is widely used for the mass production of semiconductor devices, so an improvement in throughput cannot be expected, and a fine pattern cannot be formed efficiently in a short time.
Hence, resist materials which would allow fine patterns to be formed efficiently in a short time suitable for manufacture of semiconductor devices, and their related technology, have not yet been developed in spite of the demand.